With each partner, discuss the meaning of the negative double of a one heart overcall, and the meaning of the negative double of a one spade overcall. We find that players often have quite different ideas about minimum high card strength, minimum suit length in the other major, and about whether the double promises anything about the unbid minor.
In auctions such as one heart, double by partner, two hearts, it’s important to agree whether (with four cards in an unbid major) you are expected to bid the suit versus making a responsive double.
We recommend support doubles and support redoubles. But we have found that players differ about whether — in auctions such as one diamond, pass, one spade, two clubs –opener’s support double promises extra values, a ruffing value, or both.